CORE B SUMMARY/ABSTRACT The main objective of this Core is to provide expert pathology services, in coordination with prospective processing, database tracking, storage, and optimal distribution of serial biospecimens from AML and MDS patients to support Core C and all 4 of the GAML Projects. After enrollment of AML and MDS patients by Core A (Clinical Database), bone marrow, peripheral blood leukocytes, serum/plasma, skin, and oral mucosa biospecimens are processed and banked by Core B (Specimen Database). These specimens and their derivatives will serve as the basis for genome and transcriptome analyses and immunological assays in Core C (Sequencing and Analysis) and Projects 1-4. This Biobanking Core will maintain and expand its comprehensive database that annotates each specimen with information related to histopathology, disease status, date collected/processed/distributed, processing performed, parent/derived specimen linkage, quantity, quality, and availability. All specimens are anonymously linked to the patient of origin through unique patient identifier numbers. Pathology expertise provided by Core B ensures the diagnostic accuracy of patient specimens, optimal selection of malignant and normal tissues, and maintenance of quality control (QC) and quality assurance (QA) standards and procedures within a CAP-accredited laboratory environment. Specific Aim/Core Service 1: We will prospectively process, annotate, and store serial biospecimens and derivatives from all AML and MDS patients enrolled on the GAML protocol. Procedures that are customized and validated for GAML Projects will be used. Viably cryopreserved cells will be banked for single cell RNA-seq, culture expansion, flow cytometry, and immunologic assays. We will isolate high quality DNA/RNA for genome, epigenome and transcriptome studies. Specific Aim/Core Service 2: We will provide expert pathology review and database tracking to identify and distribute biospecimens for GAML studies. Core B will use its biospecimen database to provide histopathology, disease status, quality, quantity, and availability data in real-time to enable optimal utilization the GAML Projects and Core C. Histopathology services and pathology review will ensure accurate diagnostic information, provide macro/microdissection of archived tissues, and optimal specimen selection and assembly of pathological subsets for GAML Projects.